a8c104fbb0
SPARC and MIPS CPUs don't have special instructions to count leading/trailing zeroes. The compiler-rt library provides fallback rountines for these. The 64-bit routines, __clzdi2 and __ctzdi2, are implemented as simple wrappers around the compiler built-in __builtin_clz(), assuming these will expand to either 32-bit CPU instructions or calls to __clzsi2 and __ctzsi2. Unfortunately, our GCC 4.2 probably thinks that because the operand is stored in a 64-bit register, it might just be a better idea to invoke its 64-bit equivalent, simply resulting into endless recursion. Fix this by defining __builtin_clz and __builtin_ctz to __clzsi2 and __ctzsi2 explicitly.
67 lines
2.0 KiB
C
67 lines
2.0 KiB
C
/* ===-- int_lib.h - configuration header for compiler-rt -----------------===
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*
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* The LLVM Compiler Infrastructure
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*
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* This file is dual licensed under the MIT and the University of Illinois Open
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* Source Licenses. See LICENSE.TXT for details.
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*
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* ===----------------------------------------------------------------------===
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*
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* This file is a configuration header for compiler-rt.
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* This file is not part of the interface of this library.
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*
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* ===----------------------------------------------------------------------===
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*/
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#ifndef INT_LIB_H
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#define INT_LIB_H
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/* Assumption: Signed integral is 2's complement. */
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/* Assumption: Right shift of signed negative is arithmetic shift. */
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/* Assumption: Endianness is little or big (not mixed). */
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/* ABI macro definitions */
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#if __ARM_EABI__
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# define ARM_EABI_FNALIAS(aeabi_name, name) \
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void __aeabi_##aeabi_name() __attribute__((alias("__" #name)));
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# define COMPILER_RT_ABI __attribute__((pcs("aapcs")))
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#else
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# define ARM_EABI_FNALIAS(aeabi_name, name)
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# define COMPILER_RT_ABI
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#endif
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/* Include the standard compiler builtin headers we use functionality from. */
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#include <limits.h>
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#include <stdint.h>
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#include <stdbool.h>
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#include <float.h>
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/* Include the commonly used internal type definitions. */
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#include "int_types.h"
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/* Include internal utility function declarations. */
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#include "int_util.h"
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/*
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* Workaround for LLVM bug 11663. Prevent endless recursion in
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* __c?zdi2(), where calls to __builtin_c?z() are expanded to
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* __c?zdi2() instead of __c?zsi2().
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*
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* Instead of placing this workaround in c?zdi2.c, put it in this
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* global header to prevent other C files from making the detour
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* through __c?zdi2() as well.
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*
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* This problem has only been observed on FreeBSD for sparc64 and
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* mips64 with GCC 4.2.1.
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*/
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#if defined(__FreeBSD__) && (defined(__sparc64__) || \
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defined(__mips_n64) || defined(__mips_o64))
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si_int __clzsi2(si_int);
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si_int __ctzsi2(si_int);
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#define __builtin_clz __clzsi2
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#define __builtin_ctz __ctzsi2
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#endif
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#endif /* INT_LIB_H */
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